Background: This study aims to analyze the individual laws regulating radiation risks in South Korea in order to understand the legal framework for radiation risk regulation and to propose improvements necessary for effective radiation risk regulation.Materials and Methods: This study is qualitative in nature. Expert consultations were conducted, and current laws related to radiation risk regulation were identified through the legal information center’s search engine. Previous studies on radiation risk regulation were also reviewed. First, a total of 31 individual laws related to radiation risk were identified. Second, the objectives of each law, the scope of radiation risk regulation, and the responsible administrative departments were organized. Third, the structure of the current legal framework for radiation risk regulation was organized.Results and Discussion: The legal framework for regulating radiation risks in South Korea appears to be classified into two categories. One for regulating the risks associated with nuclear power generation and another for regulating radiation risks unrelated to nuclear power plants. Although the Nuclear Safety Act is not formally classified as a fundamental law, it exhibits characteristics typically associated with such laws. In contrast, the other laws, while related to radiation safety, do not possess the characteristics of a fundamental law and are thus considered individual statutes.Conclusion: The Nuclear Safety Act functions as a fundamental law, the administrative organizations specified in this law would be able to perform functions such as risk determination, management, and judgment under the principles of a rule-of-law state, in relation to the individual laws regulating radiation risks. If it is not feasible for the Nuclear Safety Act to serve as the fundamental law, the normative systems within the individual laws regulating radiation risks must be improved to enable them to perform standardized functions for risk determination, management, and judgment.

Background: The situation in which radiation emerges uncontrollably is referred to as a radiation accident. Radiation accidents constitute emergencies that can have severe impacts on public health. Therefore, it is of critical importance for hospitals providing healthcare services to be adequately prepared for such incidents.Materials and Methods: This study aims to compare the hospital management protocols for radiation accidents in Türkiye and Japan using the strengths, weaknesses, opportunities, threats (SWOT) analysis method. As a country that has experienced a radiation accident, Japan’s post-incident developments are compared with Türkiye’s current situation. The study first examines the radiation safety regulations, healthcare policies, and hospital management strategies of both countries. While Türkiye has established general protocols under the Hospital Disaster and Emergency Plan (HAP) and for Chemical, Biological, Radiological, and Nuclear (CBRN) incidents, Japan has enhanced its crisis management and emergency response systems following the 2011 Fukushima Nuclear Accident. Within the framework of the SWOT analysis, the strengths and weaknesses of both countries, potential threats, and opportunities for improvement are analyzed in detail.Results and Discussion: This study highlights how Türkiye can benefit from Japan’s crisis management experience to enhance its preparedness for radiation accidents. The analysis reveals that Türkiye has significant shortcomings, particularly in training, drills, and hospital infrastructure. However, its investments in nuclear energy provide opportunities for development through international collaborations. On the other hand, although Japan possesses advanced radiation monitoring systems and extensive experience, it remains under constant threat due to its high concentration of nuclear power plants and exposure to natural disasters.Conclusion: To prevent radiation accidents, it is recommended to develop a hospital management model based on international standards. Additionally, effective intervention strategies should be formulated through the collaborative decision-making of hospital administrators, healthcare professionals, and policymakers to ensure a comprehensive response to radiation accidents.

Background: Radon, a radioactive gas, is ubiquitous and commonly inhaled by individuals. It was originating from the Earth's crust. Radon can also be released by building materials, water, basement air, soil, and other environmental components. When radon gas decays, it produces radioactive particles that can be inhaled. These particles damage lung tissue, increasing the risk of lung cancer over time.Materials and Methods: Indoor and outdoor radon concentrations were determined in 24 houses in two cities in Al-Najaf province, Al-Najaf city and Al-Kufa city, using Airthings Corentium Digital Radon Detector.Results and Discussion: The arithmetic mean of indoor radon concentration was 18.09±9.41 Bq/m<sup>3</sup>, while the arithmetic mean of outdoor radon concentration was 4.50±2.96 Bq/m<sup>3</sup>. The arithmetic mean of ‘the annual effective dose’ received by home occupants by indoor radon was 0.46±0.24 mSv/yr. The arithmetic mean of the ‘effective dose to the lung’ was 1.09±0.57 mSv/yr.Conclusion: The total annual effective dose due to indoor and outdoor radon concentration was lower than the reference level of International Commission on Radiological Protection. The results of the radiological survey due to indoor and outdoor radon levels in studied dwellings suggest that the radionuclides and their radiological hazard indexes in all studied dwellings do not impose a health hazard.

Background: The Health Physics Society of Japan established a working group to obtain insights and findings from articles related to the Fukushima Daiichi Nuclear Power Station (1F) accident, published in the <i>Japanese Journal of Health Physics</i>.Materials and Methods: This study describes the review results of 47 articles on opinion and others related to the 1F accident in the field other than risk communication, environmental measurement and monitoring, radiation dose measurement and assessment, radiation medicine, and radioactive waste.Results and Discussion: The reviewed articles contain various insights and issues depending on the authors’ standpoints and relevant social interests. As a result, the 1F accident-relevant articles offer various discussion points depending on the authors’ awareness of the issues and their positions, which give an opportunity to make reconsiderations on what kind of academic system health physics or radiation protection should be on the basis of the experiences from the 1F accident.Conclusion: It is crucial for the future development of the Health Physics Society of Japan and relevant academic societies and researchers to address these matters and continue to ask what health physics (or radiation protection) is.

Background: At nuclear facilities and decommissioning sites, monitoring radioactivity concentrations in airborne particulates is crucial to prevent worker exposure. To avoid internal exposure, alpha-decay radionuclides must be detected. When monitoring alpha-decay radionuclides in airborne dust, we want to measure the concentration of only artificial radionuclides (e.g. , 238Pu, 239Pu, 240Pu, 235U, 238U, 241Am, and 244Cm). The radioactivity concentration must be measured separately for artificial (4.3–5.8 MeV) and natural radionuclides (212Bi, 214Po, and 212Po at 6.0, 7.7, and 8.8 MeV, respectively).Materials and Methods: We created response functions for various alpha-ray energies using a radiation simulation toolkit. Utilizing these response functions, we deconvolved the alpha-ray energy spectra measured while collecting dust on filter paper. To ensure the precision of the response function, we prepared a model including the distance between the filter and the detector and the structure of the light shield in detail.Results and Discussion: The deconvolved spectra had three clear peaks at 6.0, 7.7, and 8.8 MeV. These energies were consistent with those of 212Bi, 214Po, and 212Po. The deconvolved energy spectra showed that only a few measurements (4.0–5.8 MeV) were included in the energy range due to artificial radionuclides. From these measurements, the decision threshold for artificial radionuclides was determined to be about 1.5×10−7 Bq/cm3.Conclusion: Our findings demonstrated that we could measure artificial and natural radionuclides separately with the deconvolved alpha-ray energy spectra. Specifically, we were able to monitor artificial radionuclides down to low radioactivity concentrations in 10-minute measurements.

Background: Boron neutron capture therapy (BNCT) is a potential radiation therapy for treating refractory cancers. Measuring the neutron energy spectrum is important to evaluate the biological effect of BNCT. We have developed a novel low-energy neutron spectrometer with a 3He position-sensitive proportional counter. The effectiveness of this spectrometer remained unvalidated due to the inadequate response function.Materials and Methods: The response function of this spectrometer was evaluated by Monte Carlo simulation to perform the validation experiment of this spectrometer. The 3He(n,p)3H reaction rate for each monochromatic neutron (energy range, 0.5 eV–10 keV) was calculated. Numerical experiments were conducted to investigate the performance of this spectrometer. Several estimated values of the energy spectrum were obtained and compared with a calculated energy spectrum at the exit of the epithermal column by the Monte Carlo simulation by preparing several candidates for signals. The Bayesian estimation algorithm was utilized for the estimation.Results and Discussion: The results indicate that the spectrometer and the evaluated response functions can be utilized to measure the energy spectrum of neutrons in the low-energy range. However, the energy spectrum could not be well represented >4 keV due to the poor response function, including uncertainties in response function calculation as well as the poor energy resolution of this detector in the high-energy region.Conclusion: The response function of the low-energy neutron spectrometer for the epithermal energy region can be assessed by the Monte Carlo simulation. The numerical experiments reveal that the effectiveness of this spectrometer can be shown in the range of 0.5 eV.

During the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station (1F) accident on March 11, 2011, many members of the Japan Health Physics Society, including researchers and radiation workers, were involved in 1F accident-related work. The resulting articles covered a wide range of topics such as lessons learned and future challenges, risk communication, environmental monitoring, dosimetry, radiation medicine, and radioactive waste. In March 2022, a working group was established to review the articles related to the 1F accident published in the <i>Japanese Journal of Health Physics</i>. This article shows the types and number of 1F-related articles published in this journal over a period of about 10 years.

Background: This study is a comparative analysis of legal decisions by the Korean judiciary regarding human health effects of radiation exposure in lawsuits related to the linear no threshold hypothesis of the International Commission on Radiological Protection (ICRP), particularly following the Fukushima nuclear power plant accident in 2011.Materials and Methods: The legal cases related to radiation exposure and human health effects were searched and compiled using legal databases such as ‘national law information center,’ ‘case note,’ and ‘LBOX.’ Keywords such as ‘radiation,’ ‘human health effects,’ ‘lawsuit,’ ‘radiation effects,’ and ‘disease’ were used to search for relevant legal cases, leading to the identification of a total of nine legal decisions. The original texts of these cases were analyzed. The analysis categorized the cases based on the distinction between the plaintiff, radiation doses, types of diseases, and the results of the lawsuits.Results and Discussion: Four lawsuits ruled that there is a causal relationship between radiation exposure and human health effects. These rulings were made in 2016 (two cases), 2018, and 2022. In cases where the radiation exposure doses were precisely recorded as 1.71 mSv and 2.09 mSv, the rulings also concluded that there was a causal relationship between radiation exposure and human health effects. In contrast, five lawsuits concluded that there was no causal relationship between low-dose radiation exposure and human health effects, ruling that a radiation exposure of 12.25 mSv was not related to the disease.Conclusion: Judicial rulings on radiation risks must be consistent and equitable. The ICRP recommends standards for radiation protection and dose limits. Based on these recommendations, the executive branch must establish consistent guidelines, and judicial rulings must maintain consistency in accordance with these standards.

Background: A NaI(Tl) survey meter was used in the pediatric thyroid screening conducted after the Fukushima Daiichi Nuclear Power Plant accident. However, this measurement method has the weakness that it is difficult to selectively identify 131I. In this study, we analyzed the performance of an energy-analyzable NaI(Tl) spectrometer using the Particle and Heavy Ion Transport code System (PHITS), which allows Monte Carlo simulation of radiation transport.Materials and Methods: The spectrum of energy emitted by the NaI(Tl) spectrometer was simulated for a total energy absorption peak by adjusting factors that affect pulse wave height. From these simulation results, the detection limits of the NaI(Tl) spectrometer were obtained using Monte Carlo simulation.Results and Discussion: The energy spectrum results were reproduced with an accuracy of 0.1% to 44.0% for total energy absorption peaks. The calculated detection limit for 131I activity equivalent to 100 mSv in the thyroid under a 0.2 μSv· hr−1 ambient dose rate was approximately 80–90 Bq, which could be detected for up to 38 days after 131I intake in a 1-year-old child.Conclusion: This study demonstrated that pediatric thyroid screening using an NaI(Tl) spectrometer can practically provide greater accuracy than NaI(Tl) survey meters.

Background: South Korea’s extensive nuclear energy capabilities, driven by 25 operational nuclear power plants (NPPs), have been instrumental in supporting industrial development. However, concerns among antinuclear activists regarding the potential risks associated with nuclear accidents have emerged. To address these concerns, this study evaluated the long-term radiological effects of a nuclear accident on individuals living near an NPP site. In particular, this study focused on the most likely type of accident, a loss of coolant accident (LOCA), assuming that it occurs in a single unit because of the rarity of simultaneous accidents across multiple units.Materials and Methods: The source terms from the LOCA comprising 131I, 134Cs, 137Cs, and 90Sr were computed using the Radiological Assessment System for Consequence AnaLysis code, and these were fed into the GENII code, which computed the annual individual effective doses and cancer incidences at various distances and directions from the NPP.Results and Discussion: The effective dose contributions from food ingestion, ground exposure, and soil particle ingestion were 86.4%, 13.5%, and 0.01%, respectively, in children and adults. Food, particularly vegetables and meat, had the greatest impact on effective doses. Regarding individuals exposed at distances of 3, 16, and 30 km from the NPP, adults received annual effective doses of 98, 19, and 12 mSv, respectively, whereas children received doses of 56, 10, and 6.6 mSv, respectively. Comparison of the computed cancer incidence with South Korea’s past 8-year data resulted in a radiation exposure contribution to cancer of 0.012%, which was significantly below the NPP safety goal of 0.1%.Conclusion: This study suggests that radiation exposure from nuclear accidents has minimal impact on cancer incidence. Therefore, restrictions on vegetable and meat consumption should be implemented after accidents to mitigate the long-term health effects of radiation exposure.